Moisture sensing system

Abstract

A sensor system for sensing a moisture level of a working fluid includes a body housing a moisture indicator that changes color in the presence of moisture. The moisture indicator has a fixed position immersed in a path of fluid flow through the body. A light source is configured to transmit light through the moisture indicator to a color-sensing sensor of the sensor system. The sensor is separated from fluid flow through the system, and the system is configured to prevent external light from affecting the sensor. The moisture indicator is manually viewable where necessary. The sensor system also is configured to provide an electric signal corresponding to the color level of the moisture indicator, to generate an alarm signal with respect to a moisture level, to adjust for change in light intensity being sensed by the sensor, and to signify if the moisture indicator is damaged or has failed.

What is claimed is: 
     
       1. A sensor system for detecting moisture in a working fluid, the sensor system comprising:
 a body configured to receive the working fluid and having a longitudinal axis extending therethrough; 
 a moisture indicator mounted in the body; 
 a light source; and 
 a sensor for receiving light passing from the moisture indicator to the sensor and initially transmitted by the light source, 
 wherein the moisture indicator is axially aligned along the longitudinal axis between the sensor and the light source. 
 
     
     
       2. The sensor system of  claim 1 , wherein the sensor system is configured to direct light transmitted from the light source to the sensor through the moisture indicator. 
     
     
       3. The sensor system of  claim 2 , wherein the sensor system is further configured to direct light initially transmitted from the light source through a light guide towards the moisture indicator. 
     
     
       4. The sensor system of  claim 1 , wherein the sensor system is configured such that the sensor detects incident light transmitted from the light source. 
     
     
       5. The sensor system of  claim 1 , wherein the moisture indicator is a color-changing indicator, and the sensor is configured to sense the color of the color-changing moisture indicator. 
     
     
       6. The sensor system of  claim 1 , wherein the sensor is a red-green-blue sensor. 
     
     
       7. The sensor system of  claim 1 , further including a cap removably attachable to the body and housing the sensor, and wherein the cap is configured to block light external to the sensor system from the sensor. 
     
     
       8. The sensor system of  claim 1 , further including a stem coupled to and received into the body, the stem disposed along the longitudinal axis between the light source and the moisture indicator, and the stem having an opaque sheath circumferentially surrounding a transparent column for directing light from the light source to the moisture indicator. 
     
     
       9. A sensor system for detecting moisture in a working fluid, the sensor system comprising:
 a body; 
 a transparent surface arranged in the body; 
 a moisture indicator mounted in the body at a first side of the transparent surface; 
 a light source positioned at a second side of the transparent surface disposed opposite the first side of the transparent surface; and 
 a light sensor disposed at the first side of the transparent surface, wherein the light source is configured to transmit light in the body and through the transparent surface and the moisture indicator towards the light sensor. 
 
     
     
       10. The sensor system of  claim 9 , wherein the sensor system is configured such that the sensor detects incident light transmitted from the light source. 
     
     
       11. The sensor system of  claim 9 , wherein the moisture indicator is a color-changing indicator and the sensor is configured to sense the color of the color-changing moisture indicator. 
     
     
       12. The sensor system of  claim 9 , further including a stem coupled to and received into the body and having the transparent surface disposed at a first end of the stem and the light source disposed at a second end of the stem disposed opposite the first end of the stem. 
     
     
       13. The sensor system of  claim 12 , wherein the stem includes an opaque sleeve disposed about a transparent core, the transparent core having the transparent surface and extending from the first end of the stem to the second end of the stem. 
     
     
       14. The sensor system of  claim 13 , wherein the sleeve is made of metal and is hermetically sealed about the transparent core. 
     
     
       15. The sensor system of  claim 9 , wherein the body further includes a bore extending between an inlet and outlet of the body, with the transparent surface and moisture indicator disposed in the bore. 
     
     
       16. The sensor system of  claim 9 , further including a cap removably attachable to the body and housing the sensor, and wherein the cap is configured to block light external to the sensor system from the light sensor. 
     
     
       17. The sensor system of  claim 9 , further including a cap disposed about the body and housing the sensor, the cap being removable from the body to allow for viewing of the moisture indicator. 
     
     
       18. The sensor system of  claim 9 , wherein the moisture indicator is coupled against the first side of the transparent surface by a coupling, and wherein the coupling prevents light leakage between the first side of the transparent surface and the moisture indicator. 
     
     
       19. A method of detecting the color of a color-changing moisture indicator, the method comprising:
 mounting a color-changing moisture indicator at a first side of a transparent surface; 
 directing light from a light source through the color-changing moisture indicator from a second side of the transparent surface disposed opposite the first side of the transparent surface; and 
 detecting, by a light sensor, the color of the color-changing moisture indicator based on the color of the light that passes through the color-changing moisture indicator. 
 
     
     
       20. The method of  claim 19 , further including transmitting the detected color of the color-changing moisture indicator by a wireless connection.